JPH01189989A - Manufacture of molded board - Google Patents

Abstract

PURPOSE:To obtain a stabilized molded board having high reliability by peeling the thin-film-shaped molded board including a conductive pattern and an electronic part unified by resin molding from a conductive board. CONSTITUTION:A conductive pattern 3 is formed onto a peeling conductive base body 1 through plating, mounting treatment in which an electronic part 7 is set up electrically and mechanically is executed onto the pattern 3, and resin molding containing the mounting section of the electronic part 7 and the conductive pattern 3, a mechanical and electrical connecting section is conducted to these part 7 and pattern 3, thus manufacturing a molded form 8. Since the conductive base body 1 is peeled finally and a molded board 18, which has only the conductive pattern 3 and the electronic part 7 and in which there is no base body, is acquired, the whole thickness can be brought to a sufficiently thin thickness corresponding to approximately the thickness of the electronic part 7, thus increasing the adhesive strength of the molded form 8 and an adhesive film 4, then improving the whole uification strength of the conductive pattern 3, the electronic part 7 and the molded form 8. Accordingly, the stabilized molded board 18 having high reliability is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a molded substrate in which an electronic component and a conductive pattern are formed as a lightweight thin film as a whole from a resin molded body.

[Summary of the invention]

The present invention involves coating a conductive pattern with a required pattern on a peelable conductive substrate, and then applying a thermosetting adhesive film having openings at the portions where electronic components and the like are electrically connected. This coating is left in a semi-cured so-called B stage state, and electronic components are mounted on it and the required parts are electrically connected to predetermined parts of the conductive pattern, and then the electronic components and A thin film of resin is molded to integrate the conductive pattern, and then a thermosetting adhesive film is heat-cured, and the resin mold is peeled off from the peeling substrate to release the electronics integrated with the thin film of the resin molded substrate. To obtain a highly reliable, lightweight, thin-film-like molded substrate as a whole by obtaining a molded substrate having a component and a conductive pattern electrically connected to the component and to which a molded body is stably adhered.

[Conventional technology]

2. Description of the Related Art There is an increasing demand for lighter, smaller, and thinner devices in various types of equipment, and along with this, there is a demand for electronic component mounting technology to make electronic component mounting boards lighter and thinner. Resin molded substrates are often used as mounting substrates for electronic components. This molded board is manufactured after mounting electronic components such as coils, semiconductor integrated circuit devices, and capacitors on a circuit board such as a flexible board or a rigid board, that is, mechanically and electrically attaching them. In order to protect these electronic components, a method has been adopted in which they are covered with a resin mold. For this reason, the entire board with electronic components mounted on it is not made of a sufficiently lightweight and thin film.For example, when used for motor parts, there is a problem with its thickness, which reduces efficiency.
A problem has arisen in that the improvement in torque is hindered.

[Problem to be solved by the invention]

The present invention solves the problem of insufficient reduction in weight and thinness of a board on which electronic components are mounted as described above, and achieves a sufficient i-film structure, thereby reducing weight and ensuring that highly reliable electronic components are mounted. The present invention aims to obtain a highly reliable molded substrate by increasing the adhesion strength of the molded body.

[Means to solve the problem]

In the present invention, as shown in FIG. 1A, a conductive substrate (
1) A process of forming a plating resist (2) with a pattern that is inverted from the conductive pattern that will serve as a mask for the electrolytic plating in the next step and that is highly removable as the final conductive pattern, as shown in FIG. 1B. As shown in FIG. An opening (4) is formed in the part of the conductive pattern (3) to which electronic components, etc. are electrically connected.
The step of forming a thermosetting insulating adhesive film 4) having a) and maintaining it in a so-called B stage semi-cured state, and the step of forming a conductive pattern (3) as shown in the first diagram.
) Coils, semiconductor integrated circuit devices, capacitors, etc. etc. are bonded to a predetermined part using, for example, a temporary adhesive (6), and a conductive pattern is attached to the conductive pattern through the opening (4a) of the adhesive liquid [11!14] using solder (5). (3) The step of electrically adhering to the predetermined part, and the step of electrically bonding the conductive substrate (
1) Resin molding is performed on the mounting part side of the upper electronic component (7) to connect the conductive pattern opening) and the electronic component (7) by embedding at least the mechanically bonded part and the electrically soldered part. There is a step of forming a thin film-like molded body (8) that is mechanically integrated, and a step of almost completely thermosetting the adhesive coating (4) at the same time or in a separate step. Thereafter, as shown in FIG. 1F, the molded body (8) containing the electronic component (7) and the conductive pattern (3) is peeled off from the conductive substrate (1), and then the desired molded substrate is obtained. (18) is obtained.

Note that the adhesive film (4) used here is a thermosetting adhesive that exhibits high adhesive strength to the mold body (8) and the conductive pattern (3).

[Effect]

According to the above-described manufacturing method of the present invention, a removable conductive substrate (
1) Form a conductive pattern (3) on top by plating,
After that, a mounting process is performed to electrically and mechanically attach the electronic component (7) thereon, and then the electronic component (7) is mounted on the electronic component (7).
7) and the conductive pattern (3), resin molding including the mounting part, that is, the mechanical and electrical connection part is performed to produce a molded body (8), and finally from this the conductive substrate (1)
is peeled off to obtain a molded substrate (18) having only the conductive pattern (3) and the electronic component (7) without any base material, so its overall thickness is almost the same as the thickness of the electronic component (7). The thickness can be made sufficiently thin to correspond to about 100 ml.

In particular, in the present invention, the resin molded body (8)
A semi-hardened adhesive film (4) is previously formed on the forming surface of the mold body (4), and the adhesive film (4) is completely cured during or after the resin molding process. 8) and the adhesive coating (4), and therefore the conductive pattern (3),
The overall integration strength of the electronic component (7) and the molded body (8) can be increased, and a stable and highly reliable molded substrate (18) can be obtained.

〔Example〕

An example in which the present invention is applied to a stator of a motor having a coil will be described in detail with reference to FIGS. 1 to 3.

A conductive substrate (1) is prepared as shown in FIG. 1A.

This conductive substrate (1) is a plate-shaped body having a conductive smooth surface, such as stainless steel, nickel, or titanium having a thickness of 50μ, from which the plated layer of the conductive pattern applied thereto can be easily peeled off. Alternatively, it may be formed of a plate-shaped body such as a nickel-based or titanium-based alloy, or a NiCo-based alloy (Kovar). Then, a plating resist (2) is formed on one smooth main surface of the conductive substrate (1) with a pattern that is an inversion of the finally obtained conductive pattern.

This plating resist (2) has a function as a mold release agent that can be easily peeled off from the conductive substrate (1), has insulating properties, and is resistant to the plating solution used during plating of the conductive pattern. It has acid resistance or alkali resistance,
A resist material such as a heat-resistant photoresist is deposited and formed into a desired pattern by, for example, a screen printing method or an optical method using a photographic technique of coating the entire surface, exposing it to light, and developing it.

Next, as shown in FIG. 1B, this plating resist (2
) on which the conductive substrate (1) is deposited, for example, is subjected to electrolytic copper plating to selectively plate the areas where the plating resist is not deposited and the surface of the conductive substrate (1) is directly exposed. A conductive pattern (3) is formed.

This conductive pattern (3) is not limited to copper plating, but can also be made of gold.

It can be formed from silver, chromium, iron, cobalt, nickel, etc. or an alloy thereof. However, in this case, the materials of the conductive pattern (3) and the conductive substrate (1) are selected by a combination of materials that are mutually highly releasable. Depending on the conductive material of this conductive pattern (3), if it is desirable to apply anti-rust treatment to the conductive pattern (3), anti-rust plating is performed in advance prior to plating of this conductive pattern (3). Further, after plating the conductive pattern (3), a metal layer plating can be laminated to prevent rust on the surface of the conductive pattern (3) and to improve adhesion of each layer formed thereon.

Next, as shown in FIG. )
A thermosetting adhesive coating (4) is formed on the other parts except for the electrical connection part (3a) of the coil terminal (17a) by screen printing or the like. This coating (4) has excellent electrical insulation, heat resistance, and solder resistance, and has the function of electrically insulating the conductive pattern (3) described later, and also prevents the flow of solder when soldering electronic components (7). It is an adhesive that has excellent adhesive strength with a resin mold, which will be described later, and can be formed by printing it to a thickness of 15 μm using silk screen printing, for example. and,
This adhesive coating (4) is kept in a B-stage semi-cured state.

Thereafter, in this example, a through hole (9) communicating with the coil center hole of the mounting portion of the coil (7) but having a smaller diameter was formed by punching out the substrate (1), for example, by punching with a die.

As shown in the first diagram, an electronic component (in this example a coil) (7) is placed on an adhesive coating (4) on a conductive pattern (3).
) on the periphery of the through hole (9) where the parts are to be attached, apply an adhesive for fixing the component plate, such as epoxy adhesive T made by ThreeBond.
82065C (curing conditions: 150°C for 11 minutes) (6)
At the same time, apply the electronic component (7) in the opening (4a).
Solder, specifically cream solder (5), is applied onto the electrical connection portions (3a) of each using, for example, a dispenser. Then, this adhesive (6) is applied to electronic components (
7) (that is, the coil) is arranged so that its center hole communicates with the through hole (9). In this case, the through hole (9) is connected to the coil (
By making the diameter smaller than the center hole of the conductive pattern (3), the electrical connection part (3a) of the coil (7) of the conductive pattern (3) faces into the center hole of the coil (7). ) are brought into contact with the required terminals (17a) of the conductive pattern (3) through the solder (5), and in this state are passed through a heating furnace, where solder paste flow treatment is performed to connect the coil terminals (17a) to the electrical conductive pattern (3). Solder the connection part (3a).

Next, as shown in FIG. 1E, resin is injection molded so as to enclose the electronic component (7) and the conductive pattern (3) to a thickness corresponding to the thickness of the electronic component (7), for example. Mold the body (8).

Next, as shown in FIG. 1F, the molded body (8) wrapped around the electronic component (7) and the conductive pattern (3) is peeled off from the conductive substrate (1) to form the desired electronic component (7). are electrically and mechanically connected on the conductive pattern (3) to obtain a thin film molded substrate (18) in which both are mechanically integrated by the molded body (8). In this way, a molded substrate (18) as a thin film stator having a motor coil whose top view is shown in FIG. 2 and whose back view is shown in FIG. 3 is formed.

Example 1 A molded substrate (1
8), a conductive substrate (1) with a thickness of 50 μm was prepared.
A stainless steel plate of 1.5 mm was used. Then, on top of this, apply 589556 manufactured by Toshi Silicone Co., Ltd. as a plating resist (2).
The RTV was deposited and formed by a silk screen method. After that, copper plating is performed to conduct a 50 μm thick conductive pattern (
3) was formed. The following was used as the plating bath composition for this copper plating. The plating conditions were as follows, and a thermosetting adhesive film (4) was applied on top of this.
was silk-screen printed and subjected to B-stage dry semi-curing at 850''C for 5 minutes.The adhesive used was Adhesive Configuration 1 having the following composition.

Adhesive Form 1 is adjusted to 50% solids in a 181 mixed solvent of cyclohexanone and xylene. This solution was obtained by dissolving the above epoxy resin and polyester resin in a 1:1 mixed solvent of cyclohexanone and xylene, and then mixing and uniformly dispersing the silica. Cream solder was printed by silk screen into the openings (4a) of the adhesive coating (4) thus formed. The electronic component (7), ie, the coil, was temporarily fixed with an ultraviolet curing adhesive (6). This adhesive (6) is T820 manufactured by ThreeBond.
A curing treatment was performed at 150° C. for 11 minutes using 65° C. Then, injection molding was performed to form a molded body (8).

The molding resin used in this case was DURANEX 3300 manufactured by Polyplastics. The injection was performed using Meiki Seisakusho 5T50/70A under the following conditions.

After this molding, after-curing was performed at 120° C. for 130 minutes to completely cure the adhesive film (4). Thereafter, the substrate (1) was peeled off.

Example 2 A method similar to Example 1 was used, but the thermosetting adhesive coating (4) was given adhesive configuration 2 below.

Adhesive Configuration 2 After the above epoxy resin and nitrile rubber were dissolved in a mixed solvent of toluene and methyl ethyl ketone (1:1), silica was mixed and uniformly dispersed to obtain a solution with a solid content of 50%. The mold resin for the mold body (8) is Duracon GB2 manufactured by Polyplastics, which is an acetal copolymer resin.
5 was used. The injection is Meiki Seisakusho 5
The test was carried out using T50/70A under the following conditions.

And so.

Example 3 A thermosetting adhesive coating (
4) was made into the following adhesive composition 3.

was reduced to 30% solids by a procedure similar to Example 1 using a 1:2:1 solvent of methanol, toluene, and acetone.
Obtained by adjusting.

Comparative Example 1 The same method as in Example 1 was used, but resist ink (manufactured by Tamura Chemical Co., Ltd., 5R29G) was used instead of the thermosetting adhesive.
It was used.

Comparative Example 2 The same method as in Example 1 was carried out, except that a thermoplastic adhesive having the following composition was used instead of the thermosetting adhesive.

The solid content was adjusted to 50% using a 1:1 mixed solvent of cyclohexanone and xylene.

Table 1 shows the measurement results of the mechanical properties of the molded substrates of the above-mentioned Examples and Comparative Examples.

Table 1 Here, the adhesion strength is the measurement result of 180° peel between the molded body (8) and the conductive pattern (3) made of a copper plating layer, and the thermal silk is measured at 60°C for 1 hour.
It was heat cycled 10 times for 1 hour at 10°C.
Mark Q indicates that no peeling was observed during this heat cycle.

In the example shown in Fig. 1, the resist (2) is finally removed together with the substrate (1) as shown in Fig. 1F. , can also be left together with the conductive pattern (3).

Furthermore, if the substrate (1
8), the adhesive liquid [l! It is also possible to form a laminated structure in which the electronic component (7) is mounted on the electronic component (7) and electrically connected to the conductive pattern (3).

Further, in the above-mentioned example, the adhesive (6) and the solder (5) are applied after the conductive pattern (3) is peeled and the thermosetting adhesive film (4) is applied. However, if the adhesive film (4) is applied, electrolytic plating is performed again to make the electrical connection part (3a) have a thickness that is approximately equal to or protrudes from the upper surface of the adhesive film (4), for example. It is also possible to electrically and mechanically attach the electronic component (7) described in the first diagram after applying conductive plating.

Further, in the above example, the present invention is applied to a case where the electronic component (7) is a motor coil and forms a stator of a motor, but a molded substrate on the rotor side of a moving coil type of a motor etc. is obtained. The present invention can be applied to various types of substrates, including cases.

〔Effect of the invention〕

As described above, in the present invention, the conductive pattern (2) is plated on the conductive substrate (1), the electronic component (7) is attached, etc. to form the resin molded body (8), and then this is By adopting a structure in which the conductive substrate (1) is peeled off, the conductive substrate (1) acts as a reinforcing plate during the manufacturing process, and as a result, the conductive pattern (3)
and the electronic component (7) can be reliably mechanically and electrically connected by the molded body (8).
Finally, a conductive substrate (1
) has been eliminated, the overall thickness of the mold body (
8), in other words, the thickness can be selected to correspond to the thickness of the electronic component (7), so that the whole can be formed into a lightweight thin film shape.

In particular, in the present invention, the resin molded body (8)
A semi-hardened adhesive film (4) is previously formed on the forming surface of the mold body (4), and the adhesive film (4) is completely cured during or after the resin molding process. 8) and the adhesive coating (4), and therefore the conductive pattern (3),
The overall integration strength of the electronic component (7) and the molded body (8) can be increased, and a stable and highly reliable molded substrate (18) can be obtained.

[Brief explanation of the drawing]

FIG. 1 C-H is a process diagram of an example of the manufacturing method of the present invention, FIGS. 2 and 3 are top and back views of an example of a stator of a motor obtained by the manufacturing method of the present invention, and FIG. 4 is a process diagram of an example of the manufacturing method of the present invention. FIG. 7 is a cross-sectional view of a molded substrate obtained by another example of the manufacturing method. (1) is a conductive substrate, (2) is a plating resist, (3)
is a conductive pattern, (4) is a thermosetting adhesive coating, and (7) is a conductive pattern.
is an electronic component, (8) is a molded body, and (18) is a molded substrate.

Claims (1)

[Claims] A step of coating a conductive substrate with a plating resist with a pattern that is inverted from the final conductive pattern, and then performing electrolytic plating on the conductive substrate to form the conductive pattern. a step of forming a semi-cured insulating thermosetting adhesive film having an opening on the conductive pattern at a portion where the electronic component etc. is electrically connected; adhesive mounting and electrically connecting the electronic component to a predetermined electrical connection portion of the conductive pattern; and resin molding the thermosetting adhesive coating on the mounting portion side of the electronic component on the substrate. A method for manufacturing a molded substrate comprising the steps of: thermally curing the conductive pattern and the electronic component integrated by the resin molding; and peeling off the thin film molded substrate including the electronic component and the conductive pattern integrated by the resin molding from the conductive substrate.